VLC

VLC RTP stream

Note: VLC can't support all video codec

Video: VP8

ffmpeg -f lavfi -i testsrc=size=640x480:rate=30:d=30 -c:v libvpx output.webm
vlc -vvv output.webm --loop --sout '#rtp{dst=127.0.0.1,port=5003}'

cat > stream.sdp << EOF
v=0
m=video 5004 RTP/AVP 96
c=IN IP4 127.0.0.1
a=rtpmap:96 VP8/90000
EOF

Use VLC player

vlc stream.sdp

Video: H264

ffmpeg -f lavfi -i testsrc=size=640x480:rate=30:d=30 -c:v libx264 -x264-params "level-asymmetry-allowed=1:packetization-mode=1:profile-level-id=42001f" output.mp4
vlc -vvv output.mp4 --loop --sout '#rtp{dst=127.0.0.1,port=5003}'

cat > stream.sdp << EOF
v=0
c=IN IP4 127.0.0.1
a=recvonly
a=type:broadcast
a=charset:UTF-8
m=video 5003 RTP/AVP 96
b=AS:43
b=RR:0
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1;profile-level-id=f4001e;sprop-parameter-sets=Z/QAHpGbKBQHtgIgAAADACAAAAeB4sWywA==,aOvjxEhE;
a=rtcp:5004
EOF

vlc stream.sdp

Audio: Opus

ffmpeg -f lavfi -i sine=frequency=1000:duration=30 -acodec libopus output.opus
vlc -vvv output.opus --loop --sout '#rtp{dst=127.0.0.1,port=5003}'

cat > stream.sdp << EOF
v=0
c=IN IP4 127.0.0.1
a=recvonly
a=type:broadcast
a=charset:UTF-8
m=audio 5003 RTP/AVP 96
b=RR:0
a=rtpmap:96 opus/48000/2
a=rtcp:5004
EOF

vlc stream.sdp